Marlier's Julie

Julidochromis marlieri is the most easily recognized species of the genus thanks to its checkerboard pattern, formed where black horizontal stripes cross vertical bands. Females reach 14–15 cm; males stay somewhat smaller. With its long, muscular body, a fin running along its back and its habit of swimming close against the rock, it is a typical Julidochromis.

Because of its size it is more self-assured and territorial than other julies. A well-matched pair breeds regularly for many years and settles at the heart of a rocky Tanganyika aquarium.

It lives along the lake's rocky shores, in crevices and hollows among large rock piles. Pairs claim their own rock group; it feeds by picking up small invertebrates inside the crevices. The water is hard, alkaline and extremely stable.

• Volume: 150 liters for a pair; 200–300 liters with other species.
• Rockwork: tall, deep rock piles with many narrow crevices and more than one cave. The rocks must be placed securely.
• Water: pH 8–9, hard and stable; a 25% water change every week.
• Substrate: fine sand.
• Lighting: moderate light; shadows among the rocks put the fish at ease.

Mainly carnivorous. A quality cichlid granule should be the staple; vary it with frozen mysis, krill, cyclops and brine shrimp. A varied diet helps keep the pattern contrast vivid.

A determined and, when necessary, fierce defender of its territory; when there are fry it chases off even fish larger than itself. It generally causes no problems with fish outside its territory.

Good companions: Cyprichromis, Paracyprichromis, Altolamprologus, Synodontis catfish; Tropheus and frontosa in a large aquarium (with adult julies).

Avoid: other Julidochromis species (they hybridize), small fish and shell-dwelling cichlids (in a small aquarium), shrimp, aggressive mbuna.

• Kept as a pair; the female is larger than the male and is the dominant partner.
• 5–6 juveniles are grown up together; the pair that forms stays and the rest are removed. Pairing adults directly often ends in fighting.
• The fry stay in the pair's territory for a while; older juveniles may help protect new fry.
• When the aquarium becomes crowded, maturing juveniles are removed; otherwise the pair attacks them.

The pair lays a few dozen eggs on the inner surface of a cave or a narrow crevice. The eggs hatch within a few days; the fry appear at the mouth of the crevice after about a week. They are fed newly hatched brine shrimp and powdered food. The parents protect the fry for a long time.

• Hardy; it becomes prone to disease in soft water and at low pH.
• Fighting within the pair: in an incompatible pair the male can be badly injured; a male that hides and refuses food should be removed immediately.
• Bloat: seen with overfeeding and a monotonous diet.

Difficult from the outside. The female is usually larger and plumper, the male more slender; some males develop a slight bump on the forehead with age. A definite distinction is made with the genital papilla.